Flame retardant compositions

ABSTRACT

Polymeric substrates, for example polyolefins such as polypropylene, can be made flame retardant by the incorporation therein of a synergistic mixture of (i.) at least one compound selected from the group consisting of nitroxyl stabilizers, hydroxylamine stabilizers, nitrone stabilizers, substituted hydroxylamine stabilizers, amine oxide stabilizers, benzofuranone stabilizers phosphite and phosphonite stabilizers, quinone methide stabilizers and monoacrylate esters of 2,2′- alkylidenebisphenol stabilizers and (ii.) at least one compound selected from the group consisting of brominated flame retardants, phosphorus containing flame retardants and inorganic flame retardants such as ammonium polyphosphate or decabromodiphenyl oxide; wherein the amount of organic or inorganic flame retardant of component (ii.) required to achieve an acceptable level of flame retardancy is significantly reduced compared to that needed when component (i.) is not present.

[0001] The instant invention pertains to a novel method of flameretarding a polymeric substrate by adding thereto an effective flameretarding amount of a mixture of a synergist compound and a knownorganic or inorganic flame retardant. The synergists are selected fromthe group consisting of the nitroxyl stabilizers, hydroxylaminestabilizers, nitrone stabilizers, substituted hydroxylamine stabilizers,amine oxide stabilizers, benzofuranone stabilizers, phosphite andphosphonite stabilizers, quinone methide stabilizers and monoacrylateesters of 2,2′-alkylidenebisphenol stabilizers.

BACKGROUND OF THE INVENTION

[0002] U.S. Pat. No. 5,393,812 describes polyolefin compositions whichare made flame retardant by a combination of a halogenated hydrocarbylphosphate or phosphonate ester flame retardant in combination with aalkoxyamine functional hindered amine, but there is no suggestion thatthe hindered amine itself is responsible for the flame retardancy, butrather that the hindered amine is preventing delustering and otherundesirable effects from occurring in these polyolefin compositions.

[0003] European Application No. 0 792 911 A2, discloses that alkoxyaminefunctional hindered amines are effective when used to enhance the flameretarding efficacy of tris(trihalogenopentyl) phosphate flameretardants.

[0004] U.S. Pat. No. 6,117,995 discloses that certain N-alkoxy hinderedamines may be used as flame retardants for organic polymers. CopendingU.S. application Ser. No. 09/502,239, filed Nov. 3,1999, and Ser. No.09/714,717, filed Nov.16, 2000, disclose the use of certain N-alkoxyhindered amines as flame retardants.

[0005] The flame retardant (FR) market today is comprised of productswhich function to interfere with the combustion process by chemicaland/or physical means. Mechanistically these FRs have been proposed tofunction during combustion of an article in either the gas phase, thecondensed phase or both. The organohalogens are proposed to generatehalogen species (e.g. HX) which interferes in the gas phase with freeradical organic “fuel” from the polymer substrate. Synergists areproposed to react with HX to form additional chemical species withinterfere with combustion in the gas phase, such as reaction of antimonyoxide with HX to form antimony halide and water vapor. Still other flameretardant classes are proposed to impart efficacy in the “condensed”phase such as forming a protective char layer on the polyester, orforming an intumescent or foaming on the polymer surface. The char orintumescent layer is thought either to prevent organic fuel frommigrating from the polymer into the vapor phase where it can fuelcombustion, or the char can act as a thermal shield to protect theunderlying polymer article from thermally induced decomposition andgeneration of fuel. Phosphorus compound of various classes (e.g. halo-or non-halogenated) are an example. Further still, other classes ofcompounds are proposed to function in the condensed and/or vapor phase.Metal hydrates or metal oxides are proposed to generate water vaporunder thermal conditions, the water acting to dilute the fuel mix in thecombustion zone and to remove heat from the flame zone via conversion ofwater to vapor. Alumina trihydrate, magnesium hydroxide or oxide, andother compounds are reported to function in this way.

[0006] These state of the art chemistries described above have variousdetrimental aspects in addition to the effective flame retardingattributes mentioned. Certain organobrominated compounds are undergovernmental scrutiny for the generation of toxic by-products during theproduction or combustion such as dioxanes from polybrominated diphenyloxides. Certain metal-containing flame retardants, notably antimonyoxides, are under scrutiny for worker exposure and toxicity reasons.Antimony oxides often contain trace amounts of arsenic compounds whichare suspected carcinogens. Overall, a growing concern has arisenregarding the generation of smoke and toxic gases which are evolved fromthese flame retardants during a fire. While the classic FRs may beeffective combustion suppressants, the toxic gases they form pose athreat to human exposure.

[0007] The instant invention alleviates some of the detrimental aspectsof the current state of the art which the use of large amounts ofcommercial flame retardants pose. The present synergist compounds arenon-halogenated and free of heavy metals, thus avoiding generation ofcorrosive HX gases and avoiding exposure to toxic metals. In someapplications, the instant invention provides a direct replacement forcurrent FR systems where the instant synergist compounds provide acomplimentary enhancement or synergistic system (e.g. antimony oxidereplacement in ABS) where good flame retardancy can be achieved by usingless classic FR agent in the presence of the instant synergistcompounds.

[0008] Hydroxylamine stabilizers are disclosed in U.S. Patent Nos.4,590,231, 4,612,393, 4,649,221, 4,668,721, 4,691,015, 4,696,964,4,703,073, 4,720,517, 4,757,102, 4,782,105, 4,831,134, 4,876,300,5,006,577, 5,019,285, 5,064,883, 5,185,448 and 5,235,056.

[0009] Nitrone stabilizers of component are described in U.S. Pat. No.4,898,901.

[0010] U.S. Pat. Nos. 4,666,962, 4,666,963, 4,678,826, 4,753,972,4,757,102, 4,760,179, 4,929,657, 5,057,563, 5,021,479, 5,045,583 and5,185,448 disclose the use of various substituted hydroxylaminestabilizers towards the stabilization of organic materials.

[0011] U.S. Patent Nos. 5,081,300, 5,162,408, 5,844,029, 5,880,191 and5,922,794 disclose the use of saturated hydrocarbon amine oxides towardsthe stabilization of thermoplastic resins.

[0012] Benzofuranone stabilizers are disclosed for example in U.S.Patent Nos. 4,325,863; 4,338,244; 5,175,312; 5,216,052; 5,252,643;5,369,159; 5,488,117; 5,356,966; 5,367,008; 5,428,162; 5,428,177;5,614,572; 5,883,165 and 5,516,920.

[0013] Quinone methide stabilizers are disclosed for example in U.S.Pat. Nos. 5,583,247, 5,616,774, 5,670,692 and 5,750,765.

[0014] O-alkenyl substituted hydroxylamine stabilizers are disclosed inU.S. Pat. No. 5,045,583.

[0015] Non-hindered alkoxyamine stabilizers are disclosed in U.S. Pat.No. 5,185,448.

DETAIL D DISCLOSURE

[0016] The instant invention pertains to a flame retardant compositionwhich comprises

[0017] (A) a polymer substrate, and

[0018] (B) an effective flame retarding amount of a synergistic mixtureof

[0019] (i.) at least one compound selected from the group consisting of

[0020] (a) nitroxyl stabilizers,

[0021] (b) hydroxylamine stabilizers,

[0022] (c) nitrone stabilizers,

[0023] (d) substituted hydroxylamine stabilizers,

[0024] (e) amine oxide stabilizers,

[0025] (e) benzofuranone stabilizers,

[0026] (g) phosphite and phosphonite stabilizers,

[0027] (h) quinone methide stabilizers and

[0028] (h) monoacrylate esters of 2,2′-alkylidenebisphenol stabilizersand

[0029] (ii.) at least one compound selected from the group consisting ofbrominated flame retardants, phosphorus containing flame retardants andinorganic flame retardants.

Component (a)

[0030] The nitroxyl stabilizers of component (a) useful in thisinvention have the generic structure

[0031] or are compounds that contain one or more groups of the formula

[0032] where each R is alkyl and T is a group required to complete a 5-or 6-membered ring.

[0033] Two or more nitroxyl groups may be present in the same moleculeby being linked through the T moiety as exemplified below where E is alinking group.

[0034] Typical nitroxyls of component (a) includebis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-ethoxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-propoxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-acetamido-1-oxyl2,2,6,6-tetramethylpiperidine,1-oxyl-2,2,6,6-tetramethylpiperidine,1-oxyl-2,2,6,6-tetramethylpiperidin-4-one,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl acetate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 2-ethylhexanoate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl stearate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl benzoate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 4-t-butyl-benzoate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) succinate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) adipate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) n-butylmalonate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) phthalate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) isophthalate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) terephthalate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) hexahydroterephthalate,N,N′bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)adipamide,N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)caprolactam,N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)dodecylsuccinimide,2,4,6-tris-[N-butyl-N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)]-s-triazine,4,4′-ethylenebis(1-oxyl-2,2,6,6-tetramethylpiperazin-4-yl)]-s-,4,4′-ethylenebis(1-oxyl-2-oxyl-1,1,3,3-tetramethyl-2-isobenzazole,1-oxyl-2,2,5,5-tetramethylpyrrolidine, andN,N-bis-(1,1,3,3-tetramethylbutyl)nitroxide.

[0035] Nitroxyl stabilizers of component (a) are for examplebis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-ethoxy1-oxyl-2,2,6,6-tetramethylpiperidine,4-propoxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-acetamido-1-oxyl-1-oxyl-2,2,6,6-tetramethylpiperidine, and1-oxyl-2,2,6,6-tetramethylpiperidin-4-one.

[0036] A specific embodiment is where the nitroxyl stabilizers ofcomponent (a) are bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacateand 4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine.

Component (b)

[0037] Hydroxylamine stabilizers of component (b) are for example thosedisclosed in U.S. Pat. Nos. 4,590,231, 4,612,393, 4,649,221, 4,668,721,4,691,015, 4,696,964, 4,703,073, 4,720,517, 4,757,102, 4,782,105,4,831,134, 4,876,300, 5,006,577, 5,019,285, 5,064,883, 5,185,448 and5,235,056, the relevant parts of which are incorporated herein byreference.

[0038] The hydroxylamine stabilizers of component (b) employed in thenovel compositions and methods are for example of the formula (I)

[0039] wherein

[0040] T₁ is straight or branched chain alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, orsaid aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms orby one or two halogen atoms; and

[0041] T₂ is hydrogen, or independently has the same meaning as T₁.

[0042] Alternatively, the hydroxylamine stabilizers of component (b) ofthe present invention are compounds that contain one or more of thegroups of the formula (II)

[0043] wherein

[0044] T is a group forming a five- or six-membered ring; and

[0045] R₁ and R₂ are independently hydrogen, alkyl of 1 to 4 carbonatoms or phenyl.

[0046] In the present invention the compounds of component (b) are, forexample, N,N-dihydrocarbylhydroxylamines of formula (I) wherein T₁ andT₂ are independently benzyl, methyl, ethyl, octyl, lauryl, dodecyl,tetradecyl, hexadecyl, heptadecyl or octadecyl, or wherein T₁ and T₂ areeach the alkyl mixture found in hydrogenated tallow amine.

[0047] The compounds of component (b) in the present compositions andmethods are, for example, N,N-dihydrocarbylhydroxylamines selected fromthe group consisting of N,N-dibenzylhydroxylamine,N,N-diethylhydroxylamine, N,N-dioctylhydroxylamine,N,N-dilaurylhydroxylamine, N,N-didodecylhydroxylamine,N,N-ditetradecylhydroxylamine, N,N-dihexadecylhydroxylamine,N,N-dioctadecylhydroxylamine, N-hexadecyl-N-tetradecylhydroxylamine,N-hexadecyl-N-heptadecylhydroxylamine,N-hexadecyl-N-octadecylhydroxylamine,N-heptadecyl-N-octadecylhydroxylamine, N-methyl-N-octadecylhydroxylamineand N,N-di(hydrogenated tallow)hydroxylamine.

[0048] Component (b) in the present invention may be for example theN,N-di(alkyl)hydroxylamine produced by the direct oxidation ofN,N-di(hydrogenated tallow)amine (Irgastab® FS-042, Ciba SpecialtyChemicals Corp.).

Component (c)

[0049] The nitrones of component (c) may be for example as described inU.S. Pat. No. 4,898,901, which is hereby incorporated by reference.

[0050] The nitrones of component (c) are for example of the formula(III)

[0051] wherein

[0052] L₁ is straight or branched chain alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, orsaid aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms orby one or two halogen atoms;

[0053] L₂ and L₃ are independently hydrogen, straight or branched chainalkyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 12 carbon atoms,aralkyl of 7 to 9 carbon atoms, or said aralkyl substituted by one ortwo alkyl of 1 to 12 carbon atoms or by one or two halogen atoms;

[0054] or L₁ and L₂ together form a five- or six-membered ring includingthe nitrogen atom.

[0055] The nitrones of component (c) may be the corresponding oxidationproducts of the hydroxylamines of component (b). That is to say, thenitrones of component (c) may be nitrone analogues of the hydroxylaminesof component (b). The nitrones may be for example,N-benzyl-α-phenylnitrone, N-ethyl-α-methylnitrone,N-octyl-α-heptylnitrone, N-lauryl-α-undecyinitrone,N-tetradecyl-α-tridcyinitrone, N-hexadecyl-α-pentadecylnitrone,N-octadecyl-α-heptadecylnitrone, N-hexadecyl-α-heptadecylnitrone,N-ocatadecyl-α-pentadecyinitrone, N-heptadecyl-α-heptadecylnitrone,N-octadecyl-α-hexadecyinitrone, N-methyl-α-heptadecylnitrone and thenitrone derived from N,N-di(hydrogenated tallow)hydroxylamine.

C mponent (d)

[0056] The substituted hydroxylamine stabilizers of component (d) arefor example those described in U.S. Pat. Nos. 4,666,962, 4,666,963,4,678,826, 4,753,972, 4,757,102, 4,760,179, 4,929,657, 5,057,563,5,021,479, 5,045,583 and 5,185,448 the disclosures of which are herebyincorporated by reference. Component (d) includes the Michael additionproducts from the reaction of the hydroxylamines of component (b) withany α,β-unsaturated ketone, ester, amide, or phosphonate. Component (d)also includes Mannich-type condensation products from the reaction ofthe hydroxylamines of component (b) with formaldehyde and secondaryamines. Component (d) also includes O-alkenyl substituted analogues ofthe present hydroxylamines of component (b) as disclosed in U.S. Pat.No. 5,045,583. Component (d) also includes non-hindered substitutedhydroxylamine stabilizers as disclosed in U.S. Pat. No. 5,185,448.Component (d) also includes acyl derivatives of the hydroxylaminestabilizers of component (b), for example such as those disclosed inU.S. Pat. No. 5,021,479.

[0057] The substituted hydroxylamines of component (d) may bederivatives of the above-described hydroxylamines of formulae (I) and(II), provided that if they are derivatives of hydroxylamines of formula(II), that they are limited to derivatives of hydroxylamines asdescribed in U.S. Pat. Nos. 5,185,448 and 5,235,056.

[0058] The present substituted hydroxylamines may be for example of theformula (IIIb) or (IIIa)

[0059] wherein

[0060] T₁ is straight or branched chain alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, orsaid aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms orby one or two halogen atoms;

[0061] T₂ is hydrogen, or independently has the same meaning as T₁; and

[0062] T₃ is allyl, straight or branched chain alkyl of 1 to 36 carbonatoms, cycloalkyl of 5 to 18 carbon atoms, cycloalkenyl of 5 to 18carbon atoms or a straight or branched chain alkyl of 1 to 4 carbonatoms substituted by phenyl or by phenyl substituted by one or two alkylgroups of 1 to 4 carbon atoms or by 1 or 2 halogen atoms.

[0063] The substituted hydroxylamines of component (d) may be forexample -allyl-N,N-dioctadecylhydroxylamine orO-n-propyl-N,N-dioctadecylhydroxylamine or N,N-di(hydrogenatedtallow)acetoxyamine.

[0064] The compounds of component (d) include the following generalstructures:

[0065] wherein

[0066] in the compounds of formula (IV)

[0067] a is 1 to 4;

[0068] R′ and R″ are independently hydrogen, alkyl of 1 to 36 carbonatoms, cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbonatoms or said aralkyl substituted by alkyl of 1 to 36 carbon atoms,

[0069] R_(b) and R_(c) are independently hydrogen or alkyl of 1 to 12carbon atoms;

[0070] A, when a=1, is a group NHR_(d), wherein Ris hydrogen, amino,alkyl of 1 to 18 carbon atoms or

[0071] where B is a direct bond or alkylene of 1 to 10 carbon atoms;

[0072] A, when a=2, is a bivalent radical of a 5-7 membered heterocycliccompound containing two nitrogen atoms in the ring, with the freevalencies on the nitrogen atoms, or is a group —N(R_(d))—B—N(R_(d))—where B and R_(d) have the meanings given above;

[0073] A, when a=3, is a group of the formula

[0074] where n is 2 to 6 and Ris hydrogen or alkyl of 1 to 4 carbonatoms; and

[0075] A, when a=4, is a group of the formula

[0076] where R_(e) and n have the meanings given above.

[0077] The R′ and R″ groups are for example hydrogen, straight-chain orbranched alkyl with 1 to 18 carbon atoms such as methyl, ethyl,n-propyl, n-butyl, tert-butyl, n-pentyl, n-octyl, 2-ethylhexyl, decyl,dodecyl and octadecyl; cyclopentyl and cyclohexyl; and benzyl,α-methylbenzyl and α,α-dimethyl-benzyl. A specific embodiment is whereR_(b) and R_(c) are hydrogen or alkyl of 1 to 4 carbon atoms.

[0078] Other specific groups include, for a=1, R_(d) as C₁-C₆ alkyl (seelist for R′ and R″) and B as C₁-C₆ alkylene; for a=2,

[0079] R_(d) as hydrogen and B as straight chain C₁-C₆ alkylene; and fora=3, A as

[0080] In compounds of formula (V), p1 R_(f), R_(g), Rand R_(i)independently are hydrogen, alkyl of 1 to 36 carbon atoms, cycloalkyl of5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms or said aralkylsubstituted by alkyl of 1 to 36 carbon atoms; and the alkali metal andalkaline earth metal salts thereof.

[0081] Specific embodiments of the R_(f)-R_(i) groups are where they areindependently straight-chain or branched alkyl with 1 to 18 carbonatoms, for instance with 1 to 12 carbon atoms such as methyl, ethyl,n-propyl, n-butyl, tert-butyl, n-pentyl, n-octyl, 2-ethylhexyl, decyl,dodecyl, tetradecyl and octadecyl; cyclopentyl and cyclohexyl; andbenzyl, α-methylbenzyl and α,α-dimethylbenzyl. Another specificembodiment are compounds having R_(t) and R_(g) as benzyl and R_(h) andR_(i) as alkyl of 1 to 8 carbon atoms. Typical salts include the sodium,potassium, calcium and magnesium salts.

[0082] In compounds of formula (VI),

[0083] R_(j) and R_(k) are independently alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9. carbon atoms orsaid aralkyl substituted by alkyl of 1 to 36 carbon atoms, or R_(j) andR_(k) together with the nitrogen can form a 5-7 member heterocyclicring, or R_(j) and R_(k) are independently a group of the formula

[0084] R_(l), R_(m), R_(n), R_(o) and R_(p) are independently hydrogen,alkyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 12 carbon atoms,allyl, aryl, aralkyl of 7 to 9 carbon atoms, said aralkyl substituted byalkyl of 1 to 36 carbon atoms, bornyl, norbornyl or isobornyl, or R_(m)and R_(n) together with nitrogen can form a 5-7 member heterocyclicring;

[0085] b is 1-4;

[0086] x is 0-5;

[0087] T_(a) is R_(l) or —CH(R_(l))—O—N(R_(j))(R_(k));

[0088] when b=1, T₆ is R_(l) or 5-7 member unsaturatedheterocyclic-substituted (C₁-C₄)alkyl, or T_(a) and T_(b) together withthe nitrogen can form a 5-7 member saturated heterocyclic ring;

[0089] when b=2, T_(b) is alkylene of 2 to 12 carbon atoms,cycloalkylene of 6 to 10 carbon atoms, arylene of 6 to 10 carbon atomsor alkylenearylenealkylene of 8 to 10 carbon atoms or T_(a) and T_(b)together with the two nitrogens can form a 5-7 member saturatedheterocyclic ring;

[0090] when b=3, T_(b) is alkanetriyl of 3 to 6 carbon atoms or T_(a)and T_(b) together with the three nitrogens can form a 5-6 membersaturated heterocyclic ring; and

[0091] when b=4, T_(b) is alkanetetriyl of 4 to 6 carbon atoms.

[0092] Representative R_(j)-R_(p) groups are straight-chain or branchedalkyl with 1 to 18 carton atoms such as methyl, ethyl, n-propyl,n-butyl, tert-butyl, n-pentyl, n-octyl, 2-ethylhexyl, decyl, dodecyl andoctadecyl; cyclopentyl or cyclohexyl; and benzyl, α-methylbenzyl andα,α-dimethylbenzyl. Specific embodiments are where R_(j) and R_(k) asbenzyl or substituted benzyl and R_(l) as hydrogen. R_(j)/R_(k) andR_(m)/R_(n) heterocyclic groups include piperidyl, pyrryl, morpholino orpyrrolidino. T_(a) is for example one of the above noted R_(j)-R_(p)representative groups or the substituted aminoxy group, while T_(b) whenb=1, may also be one of the above noted R_(j)-R_(p) groups orpyridin-2-yl alkyl. T_(a)/T_(b)(b=1) includes pyrrolidino, piperidyl andmorpholino. T_(b) when b=2 is, for example, ethylene, propylene,hexamethylene, phenylene and xylylene, and T_(a)/T_(b) heterocyclic isfor example, piperazine or pyrazolidine. T_(b) when b=3 is, for example,trimethylylpropane and T_(a) /T_(b) heterocyclic is fully saturatedtriazine or triazole. T_(b) when b=4 is, for example, pentaerythrityl.

[0093] Typical b=2 and 3 heterocyclic compounds are

[0094] A specific example of a compound of formula (V) is diethyl(N,N-dioctadecylaminoxy)ethyl phosphonate.

Comp n nt( )

[0095] The amine oxide stabilizers of component (e) are for examplethose disclosed in U.S. Pat. Nos. 5,081,300, 5,162,408, 5,844,029,5,880,191 and 5,922,794, the relevant parts of each incorporated hereinby reference.

[0096] The amine oxide stabilizers of component (e) are for examplesaturated tertiary amine oxides as represented by general formula (VII):

[0097] wherein

[0098] G₁ and G₂ are independently a straight or branched chain alkyl of6 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36carbon atoms, alkcycloalkyl of 6 to 36 carbon atoms or cycloalkylalkylof 6 to 36 carbon atoms;

[0099] G₃ is a straight or branched chain alkyl of 1 to 36 carbon atoms,aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36 carbon atoms, alkarylof 7 to 36 carbon atoms, cycloalkyl of 5 to 36 carbon atoms,alkcycloalkyl of 6 to 36 carbon atoms or cycloalkylalkyl of 6 to 36carbon atoms; and

[0100] wherein said aryl groups may be substituted by one to threehalogen, alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms orcombinations thereof; and

[0101] wherein said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyland cycloalkylalkyl groups may be interrupted by —O—, —S—, —SO—, —SO₂—,—COO—, —OCO—, —CO—, —NG₄-, —CONG₄- and NG₄CO-groups, or wherein saidalkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkylgroups may be substituted by —OG₄, —SG₄, —COOG₄, —OCOG₄, —COG₄, —N(G₄)₂,—CON(G₄)₂, —NG₄COG₄ and 5- and 6-membered rings containing the—C(CH₃)(CH₂R_(x))NL(CH₂R_(x))(CH₃)C-group or wherein said alkyl,aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkyl groupsare both interrupted and substituted by the groups mentioned above; and

[0102] wherein

[0103] G₄ is independently hydrogen or alkyl of 1 to 8 carbon atoms;

[0104] R_(x) is hydrogen or methyl;

[0105] L is hydrogen, hydroxy, C₁₋₃₀ straight or branched chain alkylmoiety, a —C(O)R moiety where R is a C₁₋₃₀ straight or branched chainalkyl group, or a —OR_(y) moiety; and

[0106] R_(y) is C₁₋₃₀ straight or branched chain alkyl, C₂-C₃₀ alkenyl,C₂-C₃₀ alkynyl, C₅-C₁₂ cycloalkyl, C₆-C₁₀ bicycloalkyl, C₅-C₈cycloalkenyl, C₆-C₁₀ aryl, C₇-C₉ aralkyl, C₇-C₉ aralkyl substituted byalkyl or aryl, or —CO(D), where D is C₁-Cl₈ alkyl, C₁-C₁₈ alkoxy,phenyl, phenyl substituted by hydroxy, alkyl or alkoxy, or amino oramino mono- or di-substituted by alkyl or phenyl.

[0107] Within compounds of the formula (VII), at least one of G₁, G₂ andG₃ contains a β-carbon-hydrogen bond, i.e. a carbon-hydrogen bond on thesecond carbon atom from the nitrogen.

[0108] The number of substituents or interrupting groups in G₁, G₂or G₃as alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl andcycloalkylalkyl defined above, if present, are from one to sixteen,within the limits given.

[0109] Examples of structures of formula (VII) are where G₁ and G₂ areindependently benzyl or substituted benzyl. It is also possible for eachof G₁, G₂, and G₃ to be the same residue. G₁ and G₂ may alsoindependently be alkyl groups of 8 to 26 carbon atoms, for example alkylgroups of 10 to 26 carbon atoms. G₃ may be an alkyl group of 1 to 22carbon atoms, for example methyl or substituted methyl. Also, thepresent amine oxides include those wherein G₁, G₂, and G₃ are the samealkyl groups of 6 to 36 carbon atoms. The aforementioned residues forG₁, G₂, and G₃ are, for instance, saturated hydrocarbon residues orsaturated hydrocarbon residues containing at least one of theaforementioned —O—, —S—, —SO—, —CO₂—, CO—, or —CON— moieties. Thoseskilled in the art will be able to envision other useful residues foreach of G₁, G₂, and G₃ without detracting from the present invention.

[0110] The saturated amine oxides of component (e) may also includespoly(amine oxides). By poly(amine oxides) is meant tertiary amine oxidescontaining at least two tertiary amine oxides per molecule. Illustrativepoly(amine oxides), also called “poly(tertiary amine oxides)”, includethe tertiary amine oxide analogues of aliphatic and alicyclic diaminessuch as, for example, 1,4-diaminobutane; 1,6-diaminohexane;1,10-diaminodecane; and 1,4diaminocyclohexane, and aromatic baseddiamines such as, for example, diamino anthraquinones anddiaminoanisoles.

[0111] Also included as component (e) are tertiary amine oxides derivedfrom oligomers and polymers of the aforementioned diamines. Useful amineoxides also include amine oxides attached to polymers, for example,polyolefins, polyacrylates, polyesters, polyamides, polystyrenes, andthe like. When the amine oxide is attached to a polymer, the averagenumber of amine oxides per polymer can vary widely as not all polymerchains need to contain an amine oxide. All of the aforementioned amineoxides may optionally contain at least one —O—, —S—, —SO—, —CO₂—, —CO—,or —CONG₄— moiety. For instance, each tertiary amine oxide of thepolymeric tertiary amine oxide may contain a C₁ residue.

[0112] The groups G₁, G₂ and G₃ of formula (VII) may be attached to amolecule containing a hindered amine. Hindered amines are known in theart and the amine oxide of the present invention may be attached to thehindered amine in any manner and structural position of the hinderedamine. Useful hindered amines when part of a compound of component (e)include those of the general formulas:

[0113] wherein L and R_(x) are as described above. Also included areamine oxides containing more than one hindered amine and more than onesaturated amine oxide per molecule. The hindered amine may be attachedto a poly(tertiary amine oxide) or attached to a polymeric substrate, asdiscussed above.

Component (f)

[0114] The benzofuranone stabilizers of component (f) are thosedisclosed for example in U.S. Pat. Nos. 4,325,863; 4,338,244; 5,175,312;5,216,052; 5,252,643; 5,369,159; 5,488,117; 5,356,966; 5,367,008;5,428,162; 5,428,177; 5,614,572; 5,883,165 or 5,516,920, allincorporated herein by reference, or3-(4-(2-acetoxyethoxy)phenyl)-5,7-di-tertbutyl-benzofuran-2-one,5,7-di-tert-butyl-3-(4-(2-stearoyloxyethoxy)phenyl)benzofuran-2-one,3,3′-bis(5,7-di-tert-butyl-3-(4-(2-hydroxyethoxy)phenyl)benzofuran-2-one),5,7-di-tert-butyl-3(4-ethoxyphenyl)benzofuran-2-one,3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one,3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butyl-benzofuran-2-one,3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one,3-(2,3-dimethylphenyl)-5,7-di-tertbutyl-benzofuran-2-one,

[0115] For example, component (f) is one or more benzofuranonestabilizers selected from:

Component (g)

[0116] Component (g) is at least one compound selected from the formulae(1), (2), (3), (4), (5), (6) and (7)

[0117] in which the indices are integral and

[0118] n is 2, 3 or 4; p is 1 or 2; q is 2 or 3; r is4 to 12; y is 1,2or 3; and z is 1 to 6;

[0119] A₁, if n is 2, is C₂-C₁₈ alkylene; C₂-C₁₂ alkylene interrupted byoxygen, sulfur or —NR₄—;

[0120] a radical of the formula

[0121] phenylene;

[0122] A₁, if n is 3, is a radical of the formula —C_(r)H₂₋₁—;

[0123] A₁ if n is 4, is

[0124] A₂ is as defined for A, if n is 2;

[0125] B is a direct bond, —CH₂—, —CHR₄—, —CR₁R₄—, sulfur,C₅-C₇cycloalkylidene, or cyclohexylidene which is substituted by from 1to 4 C₁-C₄ alkyl radicals in position 3, 4 and/or 5;

[0126] D₁, if p is 1, is C₁-C₄ alkyl and, if p is 2, is —CH₂OCH₂—;

[0127] D₂, if p is 1, is C₁-C₄ alkyl;

[0128] E, if y is 1, is C₁-C₁₈ alkyl, —OR₁ or halogen;

[0129] E, if y is 2, is —O-A₂-O—,

[0130] E, if y is 3, is a radical of the formula R₄C(CH₂O—)₃ orN(CH₂CH₂O—)₃;

[0131] Q is the radical of an at least z-valent alcohol or phenol, thisradical being attached via the oxygen atom to the phosphorus atom;

[0132] R₁, R₂ and R₃ independently of one another are C₁-C₁₈ alkyl whichis unsubstituted or substituted by halogen, —COOR₄, —CN or —CONR₄R₄;C₂-C₁₈ alkyl interrupted by oxygen, sulfur or −NR₄—; C₇-C₉phenylalkyl;C₅-C₁₂cycloalkyl, phenyl or naphthyl; naphthyl or phenyl substituted byhalogen, 1 to 3 alkyl radicals or alkoxy radicals having a total of 1 to18 carbon atoms or by C₇-C₉phenylalkyl; or a radical of the formula

[0133] in which

[0134] m is an integer from the range 3 to 6;

[0135] R₄ is hydrogen, C₁-C₁₈ alkyl, C₅-C₁₂ cycloalkyl or C₇-C₉phenylalkyl,

[0136] R₅ and R₆ independently of one another are hydrogen, C₁-C₈ alkylor C₅-C₆ cycloalkyl,

[0137] R₇ and R₈, if q is 2, independently of one another are C₁-C₄alkyl or together are a 2,3-dehydropentamethylene radical; and

[0138] R₇ and R₈, if q is 3, are methyl;

[0139] R₁₄ is hydrogen, C₁-C₉ alkyl or cyclohexyl,

[0140] R₁₅ is hydrogen or methyl and, if two or more radicals R₁₄ andR₁₅ are present, these radicals are identical or different,

[0141] X and Y are each a direct bond or oxygen,

[0142] Z is a direct bond, methylene, —C(R₁₆)₂— or sulfur, and

[0143] R₁₆ is C₁-C₈ alkyl.

[0144] Of interest are compositions and methods wherein component (g) isat least one compound selected from the formulae (1), (2), (5) and (6),in which

[0145] n is the number 2, and y is the number 1, 2 or 3;

[0146] A₁ is C₂-C₁₈ alkylene, p-phenylene or p-biphenylene,

[0147] E, if y is 1, is C₁-C₁₈ alkyl, —OR₁ or fluorine;

[0148] E, if y is 2, is p-biphenylene,

[0149] E, if y is 3, is N(CH₂CH₂O—)₃,

[0150] R₁, R₂ and R₃ independently of one another are C₁-C₁₈ alkyl,C₇-C₉ phenylalkyl, cyclohexyl, phenyl, or phenyl substituted by 1 to 3alkyl radicals having a total of 1 to 18 carbon atoms;

[0151] R₁₄ is hydrogen or C₁-C₉ alkyl,

[0152] R₁₅ is hydrogen or methyl;

[0153] X is a direct bond,

[0154] Y is oxygen,

[0155] Z is a direct bond or —CH(R₁₆)—, and

[0156] R₁₆ is C₁-C₄ alkyl.

[0157] Likewise of interest are compositions and methods whereincomponent (g) is at least one compound selected from the formulae (1),(2), (5) and (6), in which

[0158] n is the number 2 and y is the number 1 or 3;

[0159] A₁ is p-biphenylene,

[0160] E, if y is 1, is C ₁-C₁₈alkoxy or fluorine,

[0161] E, if y is 3, is N(CH₂CH₂O—)₃,

[0162] R₁, R₂ and R₃ independently of one another are C₁-C₁₈ alkyl, orphenyl substituted by 2 or 3 alkyl radicals having a total of 2 to 12carbon atoms;

[0163] R₁₄ is methyl or tert-butyl;

[0164] R₁₅ is hydrogen;

[0165] X is a direct bond;

[0166] Y is oxygen; and

[0167] Z is a direct bond, methylene or —CH(CH₃)—.

[0168] Component (g) in the present invention may be at least onecompound selected from the formulae (1), (2) and (6).

[0169] Component (g) in the present invention may be at least onecompound of the formula

[0170] in which

[0171] R₁₇ and R₁₈ independently of one another are hydrogen, C₁-C₈alkyl, cyclohexyl or phenyl, and

[0172] R₁₉ and R₂₀ independently of one another are hydrogen or C₁-C₄alkyl.

[0173] The following compounds are examples of organic phosphites andphosphonites which are suitable for use in component (g):

[0174] Triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkylphosphites, tris(nonylphenyl) phosphite (TNPP®, GE), trilaurylphosphite, trioctadecyl phosphite, distearyl pentaerythritoldiphosphite, tris(2,4-di-tert-butylphenyl) phosphite (Irgafos® 168, CibaSpecialty Chemicals Corp.), diisodecyl pentaerythritol diphosphite,bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (formula (D)),bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite(formula (E)), bisisodecyloxy-pentaerythritol diphosphite,bis(2,4-di-tert-butyl-6methylphenyl) pentaerythritol diphosphite,bis(2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tristearylsorbitol triphosphite, tetrakis (2,4-di-tert-butylphenyl)4,4′-biphenylene-diphosphonite (Irgafos® P-EPQ, Ciba Specialty ChemicalsCorp., formula (H)),6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12-dibenzo[d,g][1,3,2]dioxaphaosphepin(formula (C)),6-fluoro-2,4,8,10tetra-tert-butyl-12-methyl-dibenzo[d,g][1,3,2]dioxaphosphocin(formula (A)), bis(2,4-di-tertbutyl-6-methylphenyl) methyl phosphite,bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite (formula (G)).

[0175] The following phosphites and phosphonites may be used incomponent (g) in the novel compositions and methods:

[0176] Tris(2,4-di-tert-butylphenyl) phosphite (Irgafos® 168, CibaSpecialty Chemicals Corp.), tris(nonylphenyl) phosphite (TNPP®, GE),

[0177] Component (9) in the novel compositions and methods of thepresent invention may for example be: Tris(2,4-di-tert-butylphenyl)phosphite (Irgafos® 168, Ciba Specialty Chemicals Corp.),2,2′-ethylidenebis(2,4-di-tert-butylphenyl) fluorophosphite, (ETHANOX®398, Ethyl Corp.), bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite(Irgafos® 38, Ciba Specialty Chemicals Corp., formula (G)),bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (Ultranox® 626,GE Chemicals, formula (D)),tetrakis(2,4-di-tert-butylphenyl)4,4′-biphenylene-diphosphonite(Irgafos® P-EPQ, Ciba Specialty Chemicals Corp., formula (H)),2,2′2″-nitrilo[triethyltris(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite](Irgafos®12, Ciba Specialty Chemicals Corp., formula (B)), Ultranox® 641 (GEChemicals, formula (J)), Doverphos® S9228 (Dover Chemicals, formula (K))or Mark® HP10 (Adeka Argus, formula (L)).

[0178] These organic phosphites and phosphonites are known compounds;many of them are commercially available.

Component (h)

[0179] The quinone methide stabilizers of component (h) of the presentinvention are those disclosed for example in U.S. Pat. Nos. 5,583,247,5,616,774, 5,670,692 and 5,750,765, all incorporated herein byreference.

[0180] For example, the quinone methides of component (h) are of formula(VIII)

[0181] wherein

[0182] R₁′ and R₂′ are independently straight or branched chain alkyl of4 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or phenylalkylof 7 to 15 carbon atoms, and

[0183] R₃′ is 2-, 3- or 4-pyridyl; 2- or 3-thienyl; 2- or 3-pyrryl; 2-or 3-furyl; aryl of 6 to 10 carbon atoms; or said aryl substituted byone to three alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8 carbonatoms, alkylthio of 1 to 8 carbon atoms, alkylamino of 1 to 8 carbonatoms, dialkylamino of 2 to 8 carbon atoms, alkoxycarbonyl of 2 to 8carbon atoms, hydroxy, nitro, amino, cyano, carboxy, aminocarbonyl,chloro or mixtures of said substituents; or R₃′ is —CN, —COOH, —COOR₄′,—COR₅′, —OCOR₆′, —CONR₇′R₈′ or —PO(OR₉′)₂ where ‘R₄′ is alkyl of 1 to 18carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenyl or benzyl,

[0184] R₅′ is alkyl of 1 to 18 carbon atoms, aryl of 6 to 10 carbonatoms or said aryl substituted by 1 or 2 alkyl of 1 to 4 carbon atoms orby hydroxyl,

[0185] R₆′ is alkyl of 1 to 18 carbon atoms, aryl of 6 to 10 carbonatoms or said aryl substituted by 1 or 2 alkyl of 1 to 4 carbon atoms orby hydroxyl,

[0186] R₇′ and R₈′ are independently hydrogen, alkyl of 1 to 18 carbonatoms or said alkyl substituted by alkylamino of 1 to 4 carbon atoms, bydialkylamino of 2 to 8 carbon atoms or by hydroxyl; benzyl, aryl of 6 to10 carbon atoms or said aryl substituted by alkyl of 1 to 4 carbonatoms, by alkylamino of 1 to 4 carbon atoms, by dialkylamino of 2 to 8carbon atoms, by phenylamino or by hydroxyl, or

[0187] —NR₇′R₈′ is morpholino, piperidino or pyrrolidino, and

[0188] R₉′ is hydrogen or alkyl of 1 to 18 carbon atoms.

[0189] For example, R₁′ and R₂′ are tert-butyl, tert-amyl, tert-octyl,cyclohexyl, α-methylbenzyl or α,α-dimethylbenzyl.

[0190] A specific embodiment is where R₁′ and R₂′ are tert-butyl,tert-amyl or tert-octyl.

[0191] In the compound of formula I, R₃′ is for example phenyl or phenylsubstituted by nitro, cyano, dimethylamino, methoxy, alkyl of 1 to 4carbon atoms, hydroxy or mixtures of said substituents; specificembodiments are where R₃′ is phenyl, or where R₃′ is —CN, —COOH,—COOR₄′, —COR₅′, —OCOR₆′, —CON R₇′R₈′ or —PO(OR₉′)₂ where

[0192] R₄′ is alkyl of 1 to 8 carbon atoms,

[0193] R₅′ is methyl or phenyl,

[0194] R₆′ is alkyl of 1 to 18 carbon atoms or phenyl,

[0195] R₇′ and R₈′ are independently hydrogen or alkyl of 1 to 18 carbonatoms, or

[0196] —NR₇′R₈′ is morpholino or piperidino, and

[0197] R₉′ is alkyl of 1 to 4 carbon atoms.

[0198] R₃′ is for instance —CN, —COOH, —COOR₄′, —COR₅′, —CONR₇′R₈′ or—PO(OR₉′)₂where

[0199] R₄′ is alkyl of 1 to 4 carbon atoms,

[0200] R₅′ is methyl or phenyl,

[0201] R₇′ and R₈′ are independently hydrogen or alkyl of 1 to 4 carbonatoms, or

[0202] —NR₇′R₈′ is morpholino, and

[0203] R₉′is alkyl of 1 to 4 carbon atoms.

[0204] Specific examples of compounds of formula (VIII) are

[0205] (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetonitrile,

[0206] (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetic acid,

[0207] (3,5-di-tert-amyl-4-oxocyclohexa-2,5-dienylidene)acetic acid,

[0208] methyl (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetate,

[0209] ethyl(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetate,

[0210] n-butyl(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetate,

[0211] 2,6-di-tert-butyl-4-(2-oxopropylidene)-cyclohexa-2,5-dienone,

[0212] diethyl(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methanephosphonate,

[0213] (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methyl acetate,

[0214] (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methylpivalate,

[0215] (3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methylbenzoate, and

[0216]N,N-diethyl-2-(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetamide,

[0217] 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone,

[0218] 2,6-di-tert-butyl-4-(4-nitrobenzylidene)-cyclohexa-2,5-dienone,

[0219] 2,6-di-tert-butyl-4-(3-nitrobenzylidene)-cyclohexa-2,5-dienone,

[0220] 2,6-di-tert-butyl-4-(4-cyanobenzylidene)-cyclohexa-2,5-dienone,

[0221]2,6-di-tert-butyl-4-(4-dimethylaminobenzylidene)-cyclohexa-2,5-dienone,

[0222] 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone,

[0223] 2,6-di-tert-butyl-4-(4-methoxybenzylidene)-cyclohexa-2,5-dienone,and

[0224]2,6-di-tert-butyl-4-(3,5-di-tert-butyl-4-hydroxybenzylidene)-cyclohexa-2,5-dienone;

[0225] especially 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone.

Component (j)

[0226] The monoacrylate esters of 2,2′-alkylidenebisphenol stabilizersare for example of the formula (IX)

[0227] wherein

[0228] R₄₀, R₄₁, R₄₂, R₄₃ and R₄₄ are independently straight or branchedchain alkyl of 1 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atomsor phenylalkyl of 7 to 15 carbon atoms.

[0229] The present stabilizers of component (j) are for examplemonoacrylate esters of compounds selected from the group consisting of2,2′-methylenebis(6-tert-butyl-4-methylphenol),2,2′-methylenebis(6-tert-butyl-4-ethylphenol),2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol],2,2′-methylenebis(4-methyl-6-cyclohexylphenol),2,2′-methylenebis(6-nonyl-4-methylphenol),2,2′-methylenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol),2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],2,2′-methylenebis[6-(α-dimethylbenzyl)-4-nonylphenol],2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol and1,1-bis(3,5-dimethyl-2-hydroxyphenyl)butane.

[0230] For example, component U) may be the monoacrylate ester of2,2′-methylenebis(6-tert-butyl-4-methylphenol), available from CibaSpecialty Chemicals as Irganox® 3052:

[0231] In the structures of the present compounds of component (i.) ifany substituents are alkyl, they are for example methyl, ethyl,n-propyl, n-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl,2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl,n-tetradecyl, n-hexadecyl or n-octadecyl. Typical cycloalkyl groupsinclude cyclopentyl and cyclohexyl; typical cycloalkenyl groups includecyclohexenyl; while typical aralkyl groups include benzyl,α-methyl-benzyl, α,α-dimethylbenzyl or phenethyl.

[0232] For example, component (i.) is at least one compound selectedfrom the group consisting of

[0233] (a) bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate and4-hydroxy-1-oxyl2,2,6,6-tetramethylpiperidine,

[0234] (b) an N,N-di(alkyl)hydroxylamine produced by the directoxidation of N,N-di(hydrogenated tallow)amine (Irgastab® FS-042),

[0235] (c) N-octadecyl-α-heptadecylnitrone,

[0236] (d) O-n-propyl-N,N-dioctadecylhydroxylamine,

[0237] (e) Genox™ EP, a di(C₁₆-C₁₈)alkyl methyl amine oxide, CAS#204933-93-7,

[0238] (f) 3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one,Irganox® HP-136, (BF1),

[0239] (g) tris(2,4-di-tert-butylphenyl) phosphite (Irgafos® 168),

[0240] (h) 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone(Prostab® 6007) and

[0241] (j) the monoacrylate ester of2,2′-methylenebis(6-tert-butyl-4-methylphenol), Irganox® 3052.

[0242] Irganox, Irgafos, Prostab and Irgastab are trademarks of CibaSpecialty Chemicals. Genox™ EP is available from GE Chemicals.N-octadecyl-α-heptadecyinitrone is as prepared in Example 3 of U.S. Pat.No. 4,898,901.

[0243] The polymeric substrate of component (A) is any of a wide varietyof polymeric types including polyolefins, polystyrenics, and PVC. Forexample, the polymer substrate may be selected from the group of resinsconsisting of the polyolefins, the thermoplastic olefins, styrenicpolymers and copolymers, ABS and polymers which contain hetero atoms,double bonds or aromatic rings. Specific embodiments are where component(A) is polypropylene, polyethylene, thermoplastic olefin (TPO), ABS orhigh impact polystyrene.

[0244] For example, the polymer substrate is selected from the group ofresins consisting of the polyolefins, the thermoplastic olefins,styrenic polymers and copolymers, and ABS.

[0245] Another embodiment of the present invention is where the polymersubstrate is selected from the group consisting of polypropylene,polyethylene, thermoplastic olefin (TPO), ABS and high impactpolystyrene.

[0246] For instance, the polymer substrate is polypropylene,polyethylene or thermoplastic olefin (TPO).

[0247] Examples for polyolefins are:

[0248] 1. Polymers of monoolefins and diolefins, for examplepolypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,polyisoprene or polybutadiene, as well as polymers of cycloolefins, forinstance of cyclopentene or norbornene, polyethylene (which optionallycan be crosslinked), for example high density polyethylene (HDPE), highdensity and high molecular weight polyethylene (HDPE-HMW), high densityand ultrahigh molecular weight polyethylene (HDPE-UHMW), medium densitypolyethylene (MDPE), low density polyethylene (LDPE), linear low densitypolyethylene (LLDPE), (VLDPE) and (ULDPE).

[0249] Polyolefins, i.e. the polymers of monoolefins exemplified in thepreceding paragraph, for example polyethylene and polypropylene, can beprepared by different, and especially by the following, methods:

[0250] i) radical polymerization (normally under high pressure and atelevated temperature).

[0251] ii) catalytic polymerization using a catalyst that normallycontains one or more than one metal of groups IVb, Vb, VIb or VIII ofthe Periodic Table. These metals usually have one or more than oneligand, typically oxides, halides, alcoholates, esters, ethers, amines,alkyls, alkenyls and/or aryls that may be either p- or s-coordinated.These metal complexes may be in the free form or fixed on substrates,typically on activated magnesium chloride, titanium (III) chloride,alumina or silicon oxide. These catalysts may be soluble or insoluble inthe polymerization medium. The catalysts can be used by themselves inthe polymerization or further activators may be used, typically metalalkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metalalkyloxanes, said metals being elements of groups Ia, IIa and/or IIIa ofthe Periodic Table. The activators may be modified conveniently withfurther ester, ether, amine or silyl ether groups. These catalystsystems are usually termed Phillips, Standard Oil Indiana, Ziegler(-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).

[0252] 2. Mixtures of the polymers mentioned under 1.), for examplemixtures of polypropylene with polyisobutylene, polypropylene withpolyethylene (for example PP/HDPE, PP/LDPE) and mixtures of differenttypes of polyethylene (for example LDPE/HDPE).

[0253] 3. Copolymers of monoolefins and diolefins with each other orwith other vinyl monomers, for example ethylene/propylene copolymers,linear low density polyethylene (LLDPE) and mixtures thereof with lowdensity polyethylene (LDPE), propylene/but-1-ene copolymers,propylene/isobutylene copolymers, ethylene/but-1-ene copolymers,ethylene/hexene copolymers, ethylene/methylpentene copolymers,ethylene/heptene copolymers, ethylene/octene copolymers,propylene/butadiene copolymers, isobutylene/isoprene copolymers,ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylatecopolymers, ethylene/vinyl acetate copolymers and their copolymers withcarbon monoxide or ethylene/acrylic acid copolymers and their salts(ionomers) as well as terpolymers of ethylene with propylene and a dienesuch as hexadiene, dicyclopentadiene or ethylidene-norbornene; andmixtures of such copolymers with one another and with polymers mentionedin 1) above, for example polypropylene/ethylene-propylene copolymers,LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acrylic acidcopolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or randompolyalkylene/carbon monoxide copolymers and mixtures thereof with otherpolymers, for example polyamides.

[0254] The effective flame retarding amount of component (B) is thatneeded to show flame retarding efficacy as measured by one of thestandard methods used to assess flame retardancy. These include the NFPA701 Standard Methods of Fire Tests for Flame-Resistant Textiles andFilms, 1989 and 1996 editions; the UL 94 Test for Flammability ofPlastic Materials for Parts in Devices and Appliances, 5th Edition, Oct.29, 1996; Limiting Oxygen Index (LOI), ASTM D-2863; and ConeCalorimetry, ASTM E-1354.

[0255] In the synergistic mixture (B), component (i.) is present fromabout 0.25 to about 10% by weight based on component (A); for examplefrom about 0.5 to about 8% by weight based on component (A); for examplefrom about 0.5 to about 5% by weight based on component (A); for examplefrom about 0.5 to about 2% by weight based on component (A); for examplefrom 5.1% to about 10% by weight based on component (A); for examplefrom 5.1% to about 8% based on component (A).

[0256] In the synergistic mixture (B), component (ii.) is present fromabout 0.25 to about 60% by weight based on component (A); for examplefrom about 0.25 to about 30% by weight based on component (A); forexample from about 0.5% to about 15% by weight based on component (A);for example from about 1% to about 10% by weight based on component (A);for example from about 1% to about 5%.by weight based on component (A).

[0257] The flame retardant compounds of component (ii.) useful in theinstant invention are for instance selected from the group consisting of

[0258] tetraphenyl resorcinol diphosphite (FYROLFLEX® RDP, Akzo Nobel),

[0259] chloroalkyl phosphate esters (ANTIBLAZE® AB-1 00, Albright &Wilson; FYROL® FR-2, Akzo Nobel)

[0260] polybrominated diphenyl oxide (DE-60F, Great Lakes Corp.)

[0261] decabromodiphenyl oxide (DBDPO; SAYTEX® 102E)

[0262] antimony trioxide (Sb₂O₃),

[0263] antimony pentoxide (Sb₂O₅),

[0264] tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate (PB 370®, FMCCorp.),

[0265] triphenyl phosphate,

[0266] bis(2,3-dibromopropyl ether) of bisphenol A (PE68),

[0267] ammonium polyphosphate (APP) or (HOSTAFLAM® AP750),

[0268] resorcinol diphosphate oligomer (RDP),

[0269] brominated epoxy resin,

[0270] ethylen-bis(tetrabromophthalimide) (SAYTEX® BT-93),

[0271] bis(hexachlorocyclopentadieno)cyclooctane (DECLORANE PLUS®),

[0272] calcium sulfate

[0273] chlorinated paraffins,

[0274] magnesium carbonate,

[0275] melamine phosphates,

[0276] melamine pyrophosphates,

[0277] molybdenum trioxide,

[0278] zinc oxide,

[0279] 1,2-bis(tribromophenoxy)ethane (FF680),

[0280] tetrabromo-bisphenol A (SAYTEX® RB100),

[0281] magnesium hydroxide,

[0282] alumina trihydrate,

[0283] zinc borate,

[0284] ethylenediamine diphosphate (EDAP)

[0285] silica,

[0286] silicones,

[0287] calcium silicate,

[0288] magnesium silicate and

[0289] ethylene bis-(dibromo-norbornanedicarboximide), (SAYTEX® BN-451).

[0290] Coadditives found useful for use with the instant compounds ofcomponents (a)-(j) in flame retardant compositions are as follows:

UV Absorbers

[0291] 2-(2-hydroxy-3,5-di-α-cumylphenyl)-2H-benzotriazole, (TINUVIN®234, Ciba Specialty Chemicals Corp.);

[0292] 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, (TINUVIN® P, CibaSpecialty Chemicals Corp.);

[0293] 5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole,(TINUVIN® 327, Ciba Specialty Chemicals Corp.);

[0294] 2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole, (TINUVIN®328, Ciba Specialty Chemicals Corp.);

[0295] 2-(2-hydroxy-3-α-cumyl-5-tert-octylphenyl)-2H-benzotriazole,(TINUVIN® 928, Ciba Specialty Chemicals Corp.);

[0296] 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate,(TINUVIN® 120, Ciba Specialty Chemicals Corp.);

[0297] 2-hydroxy-4-n-octyloxybenzophenone, (CHIMASSORB® 81, CibaSpecialty Chemicals Corp.);

[0298]2,4-bis(2,4-dimethyphenyl)-6-(2-hydroxy-4-octyloxyphenyl)-s-triazine,(CYASORB® 1164, Cytec).

[0299] It is contemplated that in addition to components (i.) and (ii.)of the present compositions, that hindered amines as disclosed in U.S.Pat. No. 6,117,995 and copending U.S. application Nos. 09/502,239, filedNov. 3, 1999, and Ser. No. 09/714,717, filed Nov. 16, 2000, may also bepresent. The disclosures of this U.S. patent and applications are herebyincorporated by reference.

[0300] Certain compounds selected from components (a)-(j) are effectivealone towards providing flame retardancy to plastic substrates, forexample polyolefins, polystyrenics and PVC. In particular, compounds ofcomponent (d), certain substituted hydroxylamine stabilizers, areeffective alone as flame retardants. In particular,O-n-propyl-N,N-dioctadecylhydroxylamine is an effective flame retardantalone, that is without the presence of known flame retardants such asbrominated flame retardants, phosphorus containing flame retardants andinorganic flame retardants.

[0301] The following examples are meant for illustrative purposes onlyand are not to be construed to limit the scope of this invention in anymanner whatsoever.

Test Methods

[0302] NFPA 701 Standard Methods of Fire Tests for Flame-ResistantTextiles and Films, 1989 and 1996 editions;

[0303] UL 94 Test for Flammability of Plastic Materials for Parts inDevices and Appliances, 5th Edition, Oct. 29, 1996;

[0304] Limiting Oxygen Index (LOI), ASTM D-2863;

[0305] Cone Calorimetry, ASTM E-1 or ASTM E 1354;

[0306]

[0307] ASTM D 2633-82, burn test.

Test Compounds

[0308] NO.1 is bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,(Prostab™ 5415, Ciba Specialty Chemicals Corp.),

[0309] NOH-1 is bis(1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate,

[0310] DBDPO is decabromodiphenyl oxide,

[0311] FR-1 is tris[3-bromo-2,2-bis(bromomethyl)propyl] phosphate, (PB370®, FMC Corp.).

[0312] FR-2 is ammonium polyphosphate (APP).

[0313] FR-3 is bis(2,3-dibromopropyl) ether of tetrabromobisphenol A(PE68).

[0314] FR-4 is ammonium polyphosphate/synergist blend, HOSTAFLAM® AP750.

[0315] FR-5 is decabromodiphenyl oxide, SAYTEX® 102E.

[0316] FR-6 is ethylene bis-(tetrabromophthalimide), (SAYTEX® BT-93).

[0317] FR-7 is melamine phosphate, MELAPUR® P 46.

[0318] FR-8 is ammonium polyphosphate, EXOLIT® AP752.

EXAMPLE 1

[0319] Molding grade polypropylene is dry blended with the testadditives and then melt compounded at 425° F. (218° C.). Basestabilization is 500 ppm N,N-di(alkyl)hydroxylamine produced by thedirect oxidation of N,N-di(hydrogenated tallow)amine (Irgastab® FS-042)and 500 ppm calcium stearate. Plaques (125 mil) are prepared byinjection molding from the formulations using a Boy Injection Molder at475° F. (246° C.). The specimens are tested for flame retardancyaccording to the UL-94 vertical bum test specifications. The results areshown below.

[0320] The plaques are tested for flame retardancy by the UL 94V thicksection test. The time in seconds for the plaques to extinguish afterthe insult flame is removed is reported as “After Flame”. The time inseconds that the plaques glow after the flame incurred from the secondinsult flame is extinguished is reported as “Afterglow”. Efficacy as aflame retardant is demonstrated when low After Flame times are observedrelative to a blank sample containing no flame retardant. The averagetime for 5 samples is reported in the table below. Additive levels arereported in weight percent based on polymer. 1^(st) Formulation AdditiveAfter-flame 2^(nd) After-flame Afterglow 1 (control) none >100 xxx xxx 2  15% DBDPO 11.6  8.2 0.0   3% Sb₂O₃ 3   10% DBDPO 30.8 22.1 0.0 4   5%DBDPO >100 xxx xxx 5   5% DBDPO 14.4 48.7 0.0 0.25% NOH-1

[0321] DBDPO at the 5% level does not provide adequate flame retardancy.However, when this level of DBDPO is augmented with only 0.25% NOH-1,the flame retardancy is greatly improved.

[0322] These data show that decabromodiphenyl oxide can be replaced witha small amount of an instant hydroxylamine stabilizer in order toachieve good flame retardancy.

EXAMPLE 2

[0323] Polyethylene fibers are prepared from fiber grade polyethylene bydry blending with test additives and melt compounding at 400° F. Fibersare extruded from this formulation using a Hills laboratory scale fiberextruder. Socks are knitted from the fibers and are tested for flameretardancy according to NFPA 701 vertical burn method. Polyethylenefibers contain an additive of present components (a)-(j) in combinationwith a classic brominated flame retardant decabromodiphenyl oxide(DBDPO); bis(2,3-dibromopropyl) ether of tetrabromobis phenol A (PE68);or ethylene bis-tetrabromophthalimide (SAYTEX® BT-93). These formulatedfibers are tested for flame retardancy according to NFPA 701.

[0324] The fibers containing both an additive of components (a)-O) ofthe present invention and a classic brominated flame retardant exhibitenhanced flame retardancy compared to the classic flame retardant alone.

EXAMPLE 3

[0325] Polyethylene (LDPE) is melt compounded on a twin screw extruderat 450° F. (232° C.) with an additive of present components (a)-(j) incombination with a classic brominated flame retardant decabromodiphenyloxide (DBDPO); bis(2,3-dibromopropyl) ether of tetrabromobis phenol A(PE68); or ethylene bis-tetrabromophthalimide (SAYTEX® BT-93). 125 milplaques are compression molded at 400° F. (204° C.).

[0326] The plaques are tested for flame retardancy by the UL 94V thicksection test.

[0327] The plaques containing both an additive of components (a)-(j) ofthe present invention and a classic brominated flame retardant exhibitenhanced flame retardancy compared to the classic flame retardant alone.

EXAMPLE 4

[0328] Foam grade polyethylene is dry blended with test additives andthen melt compounded into pellets. The pelletized fully formulated resinis then blown into foam.

[0329] The polyethylene foam prepared contains an instant additive ofcomponents (a)-(j) in combination with a classic brominated flameretardant. The formulated foam is tested for flame retardancy accordingto the UL-94 burn test method.

[0330] The foam containing both an additive of present components(a)-(j) and a classic brominated flame retardant exhibits enhanced flameretardancy compared to foam containing the classic halogenated flameretardant alone.

EXAMPLE 5

[0331] Wire & cable grade polyethylene is dry blended with testadditives and then melt compounded into pellets. The pelletized fullyformulated resin is then extruded onto wire.

[0332] Test specimens are tested for flame retardancy using the ASTM D2633-82 burn test conditions. The formulations containing both acompound of the present invention selected from components (a)-(j) and aclassic brominated flame retardant exhibits enhanced flame retardancycompared to the classic halogenated flame retardant alone.

EXAMPLE 6

[0333] Fiber grade polyethylene is dry-blended with test additives. Inaddition to a compound of present components (a)-(j), selectedbrominated flame retardants are also included in the variousformulations. -Non-woven fabrics are produced from the polymer blendformulations by a spun-bonded or melt-blown process.

[0334] The non-woven fabrics made thereby are tested for flameretardancy according to the NFPA 701 vertical burn test specifications.The fabrics containing the present compounds of components (a)-(j) andselected brominated flame retardants exhibit flame retardancy.

EXAMPLE 7

[0335] Fiber grade polypropylene is dry-blended with test additives. Inaddition to a present compound of components (a)-(j), selectedbrominated flame retardants are also included in the variousformulations. Non-woven fabrics are produced from the polymer blendformulations by a spun-bonded or melt-blown process.

[0336] The non-woven fabrics made thereby are tested for flameretardancy according to the NFPA 701 vertical burn test specifications.The fabrics containing an additive selected from present components(a)-(j) and selected brominated flame retardants exhibit flameretardancy.

EXAMPLE 8

[0337] Molding grade polystyrene is dry-blended with test additives andthen melt compounded. In addition to an additive selected from presentcomponents (a)-(j), selected brominated flame retardants are alsoincluded in the test formulations. Specimens are injection molded fromthese test formulations.

[0338] The specimens are tested for flame retardancy according to theUL-94 burn test specifications. The molded specimens containing thepresent compounds of components (a)-(j) and selected brominated flameretardants exhibit flame retardancy.

EXAMPLE 9

[0339] Foam grade polystyrene is dry-blended with test additives andthen melt compounded. In addition to an additive selected from presentcomponents (a)-(j), selected brominated flame retardants are alsoincluded in these test formulations. Foam polystyrene specimens areprepared from these test formulations.

[0340] The specimens are tested for flame retardancy according to theUL-94 burn test specifications. The foam specimens containing thepresent compounds selected from components (a)-(j) and brominated flameretardants exhibit flame retardancy.

EXAMPLE 10

[0341] Molding grade ABS is dry blended with the an additive selectedfrom present components (a)-(j) and selected brominated flameretardants, then melt compounded at 425° F. (218° C.). Specimens 125 mil(⅛″) thick are then injection molded from this formulation using a BoyInjection Molder at 450° F. (232° C.). The specimens are tested forflame retardancy according to the UL-94 vertical burn testspecifications.

[0342] The specimens containing the present compounds selected fromcomponents (a)-O) and brominated flame retardants exhibit flameretardancy.

EXAMPLE 11

[0343] Fiber grade polypropylene is dry blended with an additiveselected from the present components (a)-(j) and a select brominatedflame retardant and then melt compounded at 234° C. (450° F.) intopellets. The pelletized fully formulated resin is then spun at 246° C.(475° F.) into fiber using a Hills laboratory model fiber extruder. Thespun tow of 41 filaments is stretched at a ratio of 1:3.2 to give afinal denier of 615/41.

[0344] Socks are knitted from the stabilized polypropylene fiber on aLawson-Hemphill Analysis Knitter and tested under NFPA 701 vertical burnprocedure. The time in seconds for the knitted sock to extinguish afterthe insult flame is removed is reported as “After Flame”. Both themaximum time for any one replicate and the total time for ten replicatesare measured. Efficacy as a flame retardant is demonstrated when lowAfter Flame times are observed relative to a blank sample containing noflame retardant.

[0345] The specimens containing the present compounds selected fromcomponents (a)-(j) and brominated flame retardants exhibit flameretardancy.

EXAMPLE 12

[0346] Film grade polyethylene is dry blended with the with an additiveselected from the present components (a)-(j) and a select brominatedflame retardant and then melt compounded into pellets. The pelletizedfully formulated resin is then blown at 205° C. using a MPM SuperiorBlown film extruder.

[0347] The films are tested for flame retardancy under NFPA 701 testconditions. The specimens containing the present compounds selected fromcomponents (a)-(j) and brominated flame retardants exhibit flameretardancy.

[0348] Film grade polypropylene is handled in a similar fashion andpolypropylene films containing the instant compounds and brominatedflame retardants also show flame retardancy.

EXAMPLE 13

[0349] Molded test specimens are prepared by injection moldingthermoplastic olefin (TPO) pellets containing a present test compoundselected from components (a)-(j) and a select brominated flameretardant. The TPO formulations may also contain a pigment, a phosphite,a phenolic antioxidant or hydroxylamine, a metal stearate, a UV absorberor a hindered amine stabilizer or a mixture of hindered amine and UVabsorber.

[0350] Pigmented TPO formulation composed of polypropylene blended witha rubber modifier where the rubber modifier is an in-situ reactedcopolymer or blended product containing copolymers of propylene andethylene with or without a ternary component such as ethylidenenorbornene are stabilized with a base stabilization system consisting ofan N,N-dialkylhydroxylamine or a mixture of hindered phenolicantioxidant and an organophosphorus compound.

[0351] The TPO plaques are tested for flame retardancy using the UL-94Vertical Bum conditions. A minimum of three replicates are tested.Efficacy as a flame retardant is measured relative to a blank samplecontaining no flame retardant.

[0352] The specimens containing the present compounds selected fromcomponents (a)-(j) and brominated flame retardants exhibit flameretardancy.

EXAMPLE 14

[0353] Film grade ethylene/vinyl acetate (EVA) copolymers containing 20weight percent or less of vinyl acetate are dry blended with testadditives and then melt compounded into pellets. The pelletized fullyformulated resin is then blown into a film at 205° C. using a MPMSuperior Blown-film extruder.

[0354] The films are tested for flame retardancy under NFPA 701 testconditions. The films containing the present compounds selected fromcomponents (a)-(j) and brominated flame retardants exhibit flameretardancy.

[0355] Film grade low density polyethylene (LDPE) which contains somelinear low density polyethylene (LLDPE) and/or ethylene/vinyl acetate(EVA) are dry blended with test additives and blown into film asdescribed above for EVA copolymer resin. The films are tested for flameretardancy under NFPA 701 test conditions and those containing thepresent compounds selected from components (a)-(j) and brominated flameretardants exhibit flame retardancy.

EXAMPLE 15

[0356] High impact polystyrene (HIPS) polymer (STYRON® 484C, DowChemical Co.) is compounded with a present compound of components(a)-(j) and a select brominated flame retardant, pelletized and theninjection or compression molded into plaques. These plaques are testedfor flame retardant efficacy using cone calorimetry, LOI or UL-94 testmethod.

[0357] The plaques containing an instant compound of component (a)-(j)and a select brominated flame retardant exhibit flame retardancy. Flameretardant HIPS polymers find application in housings for businessmachines.

EXAMPLE 16

[0358] This Example shows the efficacy of the present compounds in PVCformulations. Such formulations are useful in flexible or rigid PVC andin wire and cable applications.

[0359] Typical formulations are seen below: Component parts parts partsparts PVC resin 100 100 100 100 tin mercaptide 1.5 — 2.0 — tincarboxyate — 2.5 — 2.0 process aid 1.5 1.5 2.0 2.0 impact mod. 6.0 6.07.0 7.0 paraffin wax 1.0 0.3 1.0 1.0 polyethyl wax 0.1 0.1 0.2 0.2 Castearate 1.0 — 0.8 — pigment 1.0 0.9 5.0 5.0

[0360] Fully formulated PVC containing the present compounds ofcomponents (a)-(j) and a known organic or inorganic flame retardant ispelletized and then injection molded into test plaques for examinationof flame retardancy using the UL-94 or LOI test method.

[0361] The PVC plaques containing the instant compounds of components(a)-(j) and a classic organic or inorganic flame retardant demonstrateflame retardancy.

EXAMPLE 17

[0362] Fiber grade poly(ethylene terephthalate) (PET) is dry blendedwith test additives of components (a)-(j) and a classic flame retardant,then melt compounded at 550° F. and then pelletized. The polyesterpellets are dried at 175° F. for 24 hours under vacuum. The driedpellets are extruded into fibers using a Hills laboratory scale fiberextruder at 550° F. Socks are knitted from these fibers and tested forflame retardancy according to NFPA 701 test method.

[0363] The fibers containing both a present compound of components(a)-(j) and a classic halogenated or phosphorus flame retardant exhibitenhanced flame retardancy compared to the classic flame retardant alone.

EXAMPLE 18

[0364] Thermoplastic resins including polypropylene, polyethylenehomopolymer, polyolefin copolymer or thermoplastic olefins (TPO), highimpact polystyrene (HIPS) and ABS are dry blended with the instantcompounds of components (a)-(j) and a classic organic or inorganic flameretardant and then melt compounded into pellets. The pelletized fullyformulated resin is then processed into a useful article such asextrusion into fiber; blown or cast extrusion into film; blow moldedinto bottles; injection molded into molded articles, thermoformed intomolded articles, extruded into wire and cable housing or rotation moldedinto hollow articles.

[0365] The articles containing the instant compounds of components(a)-(j) and a known organic or inorganic flame retardant exhibit flameretardancy when tested by a known standard test method.

[0366] Polyethylene wire and cable applications are tested for flameretardancy according to ASTM D-2633-82 burn test method. The materialscontaining the instant compounds of components (a)-(j) and a knownorganic or inorganic flame retardant show flame retardancy.

EXAMPLE 19

[0367] Articles prepared according to Example 18 which additionallycontain an organophosphorus stabilizer selected from the groupconsisting of tris(2,4-di-tert-butylphenyl) phosphite,bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite,2,2′,2″-nitrilo[triethyl-tris-(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl) phosphite],tetrakis(2,4-di-butylphenyl) 4,4′-biphenylenediphosphonite,tris(nonylphenyl) phosphite, bis(2,4-di-tert-butylphenyl)pentaerythrityl diphosphite, 2,2′-ethylidenebis(2,4-di-tert-butylphenyl)fluorophosphite and 2-butyl-2-ethylpropan-1,3-diyl,2,4,6-tri-tert-butylphenyl phosphite exhibit good flame retardancyproperties.

EXAMPLE 20

[0368] Articles prepared according to Example 18 which additionallycontain a o-hydroxyphenyl-2H-benzotriazole, a hydroxyphenyl benzophenoneor a o-hydroxyphenyl-s-triazine UV absorber selected from the groupconsisting of 2-(2-hydroxy-3,5-di-α-cumylphenyl)-2H-benzotriazole,2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole,5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole,2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole,2-(2-hydroxy-3-α-cumyl-5-tert-octylphenyl)-2H-benzotriazole,2,4-di-tert-butylphenyl 3,5-di-tert-butyl4-hydroxybenzoate,2-hydroxy-4-n-octyloxybenzophenone and2,4-bis(2,4-dimethyphenyl)-6-(2-hydroxy-4-octyloxyphenyl)-s-triazineexhibit good flame retardancy.

EXAMPLE 21

[0369] Articles prepared according to Example 18 which additionallycontain a o-hydroxyphenyl-2H-benzotriazole, a hydroxyphenyl benzophenoneor a o-hydroxyphenyl-s-triazine UV absorber selected from the groupconsisting of 2-(2-hydroxy-3,5-di-α-cumylphenyl)-2H-benzotriazole,2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole,5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole,2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole,2-(2-hydroxy-3-α-cumyl-5-tert-octylphenyl)-2H-benzotriazole,2,4-di-tert-butylphenyl 3,5-di-tert-butyl4-hydroxybenzoate,2-hydroxy-4-n-octyloxybenzophenone and2,4-bis(2,4-dimethyphenyl)-6-(2-hydroxy-4-octyloxyphenyl)-s-triazine,exhibit good flame retardancy properties.

EXAMPLE 22

[0370] Examples 1-21 are repeated where the compound of components(a)-(j) is selected from

[0371] (a) bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine

[0372] (b) an N,N-di(alkyl)hydroxylamine produced by the directoxidation of N,N-di(hydrogenated tallow)amine (Irgastab® FS-042),

[0373] (c) N-octadecyl-α-heptadecyinitrone,

[0374] (d) O-n-propyl-N,N-dioctadecylhydroxylamine,

[0375] (e) Genox® EP, a di(C₁₆-C₁₈)alkyl methyl amine oxide, CAS#204933-93-7,

[0376] (f) 3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one,Irganox® HP-136, (BF1),

[0377] (g) tris(2,4-di-tert-butylphenyl) phosphite (Irgafos® 168),

[0378] (h) 2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone(Prostab™6007) and

[0379] (j) the monoacrylate ester of2,2′-methylenebis(6-tert-butyl-4-methylphenol), Irganox® 3052.

[0380] Formulations containing an instant stabilizer of components(a)-(j) and a brominated flame retardant achieve good flame retardancy.

EXAMPLE 23

[0381] Examples 1-22 are repeated where the classic flame retardant is aflame retardant such as bis(2,3-dibromopropyl) ether of bisphenol A(PE68), tris[3-bromo-2,2,-bis(bromo-methyl)propyl] phosphate (PB370),ethylene bis-tetrabromophthalimide (SAYTEX BT-93) or ethylenebis-dibromonorbornanedicarboximide (SAYTEX BN-451). Other formulationsmay contain antimony trioxide in addition to brominated flameretardants. Other formulations may contain phosphorus based flameretardants such as ethylenediamine diphosphate (EDAP) or ammoniumpolyphosphate (APP) instead of a brominated flame retardant.

[0382] The samples containing the present compounds selected fromcomponents (a)-(j) and classic flame retardants exhibit flameretardancy.

EXAMPLE 24

[0383] Example 1 is repeated with the test additives of the table below.Additive levels are reported in weight percent based on polymer. Theaverage of 2 or 3 samples are reported. Formulation Additive 1^(st)After-flame 2^(nd) After-flame  1 (control) none burns xxx  6 1% NO•1 0burns  7 1% NOH-1 1.2 burns  8 1% NOR-1 burns xxx  9 3% FR-1 0 burns 104% FR-1 0 burns 11 5% DBDPO 2.2 burns 12 6% DBDPO 2.1 burns 13 3% FR-1 050.5 1% NOR-1 14 5% DBDPO 0.2  6.8 1% NO•1 15 5% DBDPO 0.4 19.5 1% NOH-1

What is claimed is:
 1. A flame retardant composition which comprises (A)a polymer substrate, and (B) an effective flame retarding amount of asynergistic mixture of (i.) at least one compound selected from thegroup consisting of (a) nitroxyl stabilizers, (b) hydroxylaminestabilizers, (c) nitrone stabilizers, (d) substituted hydroxylaminestabilizers of the formula (IIIb) or (IIIa)

wherein T₁ is straight or branched chain alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, orsaid aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms orby one or two halogen atoms; T₂ is hydrogen, or independently has thesame meaning as T₁; and T₃ is allyl, straight or branched chain alkyl of1 to 36 carbon atoms, cycloalkyl of 5 to 18 carbon atoms, cycloalkenylof 5 to 18 carbon atoms or a straight or branched chain alkyl of 1 to 4carbon atoms substituted by phenyl or by phenyl substituted by one ortwo alkyl groups of 1 to 4 carbon atoms or by 1 or 2 halogen atoms; (e)amine oxide stabilizers, (f) benzofuranone stabilizers, (g) phosphiteand phosphonite stabilizers, (h) quinone methide stabilizers and (j)monoacrylate esters of 2,2′-alkylidenebisphenol stabilizers and (ii.) atleast one compound selected from the group consisting of brominatedflame retardants, phosphorus containing flame retardants and inorganicflame retardants.
 2. A composition according to claim 1 whereincomponent (i.) of the synergistic mixture (B) is selected from a)nitroxyl stabilizers of the formula

or nitroxyl stabilizers that contain one or more groups of the formula

where each R is alkyl of 1 to 4 carbon atoms and T is a group requiredto complete a 5- or 6-membered ring; b) hydroxylamine stabilizers of theformula (I)

wherein T₁ is straight or branched chain alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, orsaid aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms orby one or two halogen atoms; and T₂ is hydrogen, or independently hasthe same meaning as T₁; or hydroxylamine stabilizers that contain one ormore of the groups of the formula (11)

wherein T is a group forming a five- or six-membered ring; and R₁ and R₂are independently hydrogen, alkyl of 1 to 4 carbon atoms or phenyl; c)nitrone stabilizers of the formula (III)

wherein L₁ is straight or branched chain alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, orsaid aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms orby one or two halogen atoms; L₂ and L₃ are independently hydrogen,straight or branched chain alkyl of 1 to 36 carbon atoms, cycloalkyl of5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, or said aralkylsubstituted by one or two alkyl of 1 to 12 carbon atoms or by one or twohalogen atoms; or L₁ and L₂ together form a five- or six-membered ringincluding the nitrogen atom; d) hydroxylamines of the formula (IIIb) or(IIIa)

wherein T₁ is straight or branched chain alkyl of 1 to 36 carbon atoms,cycloalkyl of 5 to 12 carbon atoms, aralkyl of 7 to 9 carbon atoms, orsaid aralkyl substituted by one or two alkyl of 1 to 12 carbon atoms orby one or two halogen atoms; T₂ is hydrogen, or independently has thesame meaning as T₁; and T₃ is allyl, straight or branched chain alkyl of1 to 36 carbon atoms, cycloalkyl of 5 to 18 carbon atoms, cycloalkenylof 5 to 18 carbon atoms or a straight or branched chain alkyl of 1 to 4carbon atoms substituted by phenyl or by phenyl substituted by one ortwo alkyl groups of 1 to 4 carbon atoms or by 1 or 2 halogen atoms; e)amine oxide stabilizers of formula (VII)

wherein G₁ and G₂ are independently a straight or branched chain alkylof 6 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to36 carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36carbon atoms, alkcycloalkyl of 6 to 36 carbon atoms or cycloalkylalkylof 6 to 36 carbon atoms; G₃ is a straight or branched chain alkyl of 1to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36carbon atoms, alkcycloalkyl of 6 to 36 carbon atoms or cycloalkylalkylof 6 to 36 carbon atoms; and wherein said aryl groups may be substitutedby one to three halogen, alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8carbon atoms or combinations thereof; and wherein said alkyl, aralkyl,alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkyl groups may beinterrupted by —O—, —S—, —SO—, —SO₂—, —COO−, —OCO—, —CO—, —NG₄-, —CONG₄-and NG₄CO— groups, or wherein said alkyl, aralkyl, alkaryl, cycloalkyl,alkcycloalkyl and cycloalkylalkyl groups may be substituted by —OG₄,—SG₄, —COOG₄, —OCOG₄, —COG₄, —N(G₄)₂, —CON(G₄)₂, —NG₄COG₄ and 5- and6-membered rings containing the —C(CH₃)(CH₂R_(x))NL(CH₂R_(x))(CH₃)C—group or wherein said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyland cycloalkylalkyl groups are both interrupted and substituted by thegroups mentioned above; and wherein G₄ is independently hydrogen oralkyl of 1 to 8 carbon atoms; R_(x) is hydrogen or methyl; L ishydrogen, hydroxy, C₁₋₃₀ straight or branched chain alkyl moiety, a—C(O)R moiety where R is a C₁₋₃₀ straight or branched chain alkyl group,or a —OR_(y) moiety; and Ris C₁₋₃₀ straight or branched chain alkyl,C₂-C₃₀ alkenyl, C₂-C₃₀ alkynyl, C₅-C₁₂ cycloalkyl, C₆-C₁₀ bicycloalkyl,C₅-C₈ cycloalkenyl, C₆-C₁₀ aryl, C₇-C₉ aralkyl, C₇-C₉ aralkylsubstituted by alkyl or aryl, or —CO(D), where D is C₁-C₁₈ alkyl, C₁-C₁₈alkoxy, phenyl, phenyl substituted by hydroxy, alkyl or alkoxy, or aminoor amino mono- or di-substituted by alkyl or phenyl; f) benzofuranonestabilizers; g) phosphite and/or phosphonite stabilizers of the formulae(1), (2), (3), (4), (5), (6) and (7)

in which the indices are integral and n is 2,3 or 4; p is 1 or 2; q is 2or 3; r is 4 to 12; y is 1,2 or 3; and z is 1 to 6; A₁, if n is 2, isC₂-C₁₈ alkylene; C₂-C₁₂ alkylene interrupted by oxygen, sulfur or —NR₄—;a radical of the formula

phenylene; A₁, if n is 3, is a radical of the formula —C_(r)H_(2r-1)—;A₁, if n is 4,is

A₂ is as defined for A₁ if n is 2; B is a direct bond, —CH₂—, —CHR₄—,—CR₁₁R₄—, sulfur, C₅-C₇cycloalkylidene, or cyclohexylidene which issubstituted by from 1 to 4 C₁-C₄alkyl radicals in position 3, 4 and/or5; D₁, if p is 1, is C₁-C₄ alkyl and, if p is 2, is —CH₂OCH₂—; D₂, if pis 1, is C₁-C₄ alkyl; E, if y is 1, is C₁-C₁₈alkyl, —OR₁₁ or halogen; E,if y is 2, is —O-A₂-O—, E, if y is 3, is a radical of the formulaR₄C(CH₂O—)₃ or N(CH₂CH₂O—)₃; Q is the radical of an at least z-valentalcohol or phenol, this radical being attached via the oxygen atom tothe phosphorus atom; R₁₁, R₁₂ and R₃ independently of one another areC₁-C₁₈ alkyl which is unsubstituted or substituted by halogen, —COOR₄,—CN or —CONR₄R₄; C₂-C₁₈ alkyl interrupted by oxygen, sulfur or—NR₄—;C₇-C₉ phenylalkyl; C₅-C₁₂ cycloalkyl, phenyl or naphthyl; naphthylor phenyl substituted by halogen, 1 to 3 alkyl radicals or alkoxyradicals having a total of 1 to 18 carbon atoms or by C₇-C₉ phenylalkyl;or a radical of the formula

in which m is an integer from the range 3 to 6; R₄ is hydrogen, C₁-C₁₈alkyl, C₅-C₁₂ cycloalkyl or C₇-C₉ phenylalkyl, R₅ and R₆ independentlyof one another are hydrogen, C₁-C₈ alkyl or C₅-C₆ cycloalkyl, R₇ and R₈,if q is 2, independently of one another are C₁-C₄ alkyl or together area 2,3-dehydropentamethylene radical; and R₇ and R₈, if q is 3, aremethyl; R₁₄ is hydrogen, C₁-C₉ alkyl or cyclohexyl, R₁₅ is hydrogen ormethyl and, if two or more radicals R₁₄ and R₁₅ are present, theseradicals are identical or different, X and Y are each a direct bond oroxygen, Z is a direct bond, methylene, —C(R₁₆)₂— or sulfur, and R₁₆ isC₁-C₈alkyl; h) quinone methide stabilizers of formula (VII)

wherein R₁′ and R₂′ are independently straight or branched chain alkylof 4 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms orphenylalkyl of 7 to 15 carbon atoms, and R₃′ is 2-, 3- or 4-pyridyl; 2-or 3-thienyl; 2- or 3-pyrryl; 2- or 3-furyl; aryl of 6 to 10 carbonatoms; or said aryl substituted by one to three alkyl of 1 to 8 carbonatoms, alkoxy of 1 to 8 carbon atoms, alkylthio of 1 to 8 carbon atoms,alkylamino of 1 to 8 carbon atoms, dialkylamino of 2 to 8 carbon atoms,alkoxycarbonyl of 2 to 8 carbon atoms, hydroxy, nitro, amino, cyano,carboxy, aminocarbonyl, chloro or mixtures of said substituents; or R₃′is —CN, —COOH, —COOR₄′, —COR₅′, —OCOR₆′, ′CONR₇′R₈′ or —PO(OR₉′)₂ whereR₄′ is alkyl of 1 to 18 carbon atoms, cycloalkyl of 5 to 12 carbonatoms, phenyl or benzyl, R₅′is alkyl of 1 to 18 carbon atoms, aryl of 6to 10 carbon atoms or said aryl substituted by 1 or 2 alkyl of 1 to 4carbon atoms or by hydroxyl, R₆′ is alkyl of 1 to 18 carbon atoms, arylof 6 to 10 carbon atoms or said aryl substituted by 1 or 2 alkyl of 1 to4 carbon atoms or by hydroxyl, R₇′ and R₈′ are independently hydrogen,alkyl of 1 to 18 carbon atoms or said alkyl substituted by alkylamino of1 to 4 carbon atoms, by dialkylamino of 2 to 8 carbon atoms or byhydroxyl; benzyl, aryl of 6 to 10 carbon atoms or said aryl substitutedby alkyl of 1 to 4 carbon atoms, by alkylamino of 1 to 4 carbon atoms,by dialkylamino of 2 to 8 carbon atoms, by phenylamino or by hydroxyl,or —NR₇′R₈′ is morpholino, piperidino or pyrrolidino, and R₉′ ishydrogen or alkyl of 1 to 18 carbon atoms; j) monoacrylate esters of theformula (IX)

wherein R₄₀, R₄₁, R₄₂, R₄₃ and R₄₄ are independently straight orbranched chain alkyl of 1 to 18 carbon atoms, cycloalkyl of 5 to 12carbon atoms or phenylalkyl of 7 to 15 carbon atoms.
 3. A compositionaccording to claim 2 wherein component (i.) of the synergistic mixture(B) is selected from a) nitroxyl stabilizers selected from the groupconsisting of bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-ethoxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-propoxy-1-oxyl-2,2,6,6-tetramethylpiperidine,4-acetamido-1-oxyl-2,2,6,6-tetramethylpiperidine,1-oxyl2,2,6,6-tetramethylpiperidin-4-one,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl acetate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 2-ethylhexanoate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl stearate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl benzoate,1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 4-t-butyl-benzoate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) succinate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) adipate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4n-butylmalonate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) phthalate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) isophthalate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) terephthalate,bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) hexahydroterephthalate,N,N′-bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)adipamide,N-(1-oxyl-2,2,6,6-tetramethylpoperdin-4-yl)caprolactam,N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)dodecylsuccinimide,2,4,6-tris-[N-butyl-N-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)]-s-triazine,4,4′-ethylenebis(1-oxyl-2,2,6,6-tetramethylpiperazin-3-one),2-oxyl-1,1,3,3-tetramethyl-2-isobenzazole,1-oxyl-2,2,5,5-tetramethylpyrrolidine, andN,N-bis-(1,1,3,3-tetramethylbutyl)nitroxide; b) hydroxylaminestabilizers of the formula (I), wherein T₁ and T₂ are independentlybenzyl, methyl, ethyl, octyl, lauryl, dodecyl, tetradecyl, hexadecyl,heptadecyl or octadecyl, or wherein T₁ and T₂ are each the alkyl mixturefound in hydrogenated tallow amine; c) nitrones selected from the groupconsisting of N-benzyl-α-phenylnitrone, N-ethyl-α-methylnitrone,N-octyl-α-heptylnitrone, N-lauryl-α-undecylnitrone,N-tetradecyl-α-tridcylnitrone, N-hexadecyl-α-pentadecylnitrone,N-octadecyl-α-heptadecylnitrone, N-hexadecyl-α-heptadecyinitrone,N-ocatadecyl-α-pentadecylnitrone, N-heptadecyl-α-neptadecyinitrone,N-octadecyl-α-hexadecyinitrone, N-methyl-α-heptadecyinitrone and thenitrone derived from N,N-di(hydrogenated tallow)hydroxylamine; d)hydroxylamines selected from the group consisting of compounds of theformula (IV), (V) and (VI)

wherein in the compounds of formula (IV) a is 1 to 4; R′ and R″ areindependently hydrogen, alkyl of 1 to 36 carbon atoms, cycloalkyl of 5to 12 carbon atoms, aralkyl of 7 to 9-carbon atoms or said aralkylsubstituted by alkyl of 1 to 36 carbon atoms, R_(b) and R_(c) areindependently hydrogen or alkyl of 1 to 12 carbon atoms; A, when a=1, isa group NHR_(d) , wherein R_(d) is hydrogen, amino, alkyl of 1 to 18carbon atoms or

where B is a direct bond or alkylene of 1 to 10 carbon atoms; A, whena=2, is a bivalent radical of a 5-7 membered heterocyclic compoundcontaining two nitrogen atoms in the ring, with the free valencies onthe nitrogen atoms, or is a group —N(R_(d))—B—N(R_(d) ) where B andR_(d) have the meanings given above; A, when a=3, is a group of theformula

where n is 2 to 6 and Re is hydrogen or alkyl of 1 to 4 carbon atoms;and A, when a=4, is a group of the formula

in compounds of formula (V), R_(f), R_(g), R_(h) and R_(i) independentlyare hydrogen, alkyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 12carbon atoms, aralkyl of 7 to 9 carbon atoms or said aralkyl substitutedby alkyl of 1 to 36 carbon atoms; and the alkali metal and alkalineearth metal salts thereof; in compounds of formula (VI), R_(j) and R_(k)are independently alkyl of 1 to 36 carbon atoms, cycloalkyl of 5 to 12carbon atoms, aralkyl of 7 to 9 carbon atoms or said aralkyl substitutedby alkyl of 1 to 36 carbon atoms, or R_(j) and R_(k) together with thenitrogen can form a 5-7 member heterocyclic ring, or R_(j) and R_(k) areindependently a group of the formula

R_(l), R_(m) , R_(n), R_(o) and R_(p) are independently hydrogen, alkylof 1 to 36 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, allyl,aryl, aralkyl of 7 to 9 carbon atoms, said aralkyl substituted by alkylof 1 to 36 carbon atoms, bornyl, norbornyl or isobornyl, or R_(m) andR_(n) together with nitrogen can form a 5-7 member heterocyclic ring; bis 1-4; x is 0-5; T_(a) is R_(i) or —CH(R_(l))—O—N(R_(j))(R_(k)); whenb=1, T_(b) is R_(l) or 5-7 member unsaturated heterocyclic-substituted(C₁-C₄)alkyl, or T_(a) and T_(b) together with the nitrogen can form a5-7 member saturated heterocyclic ring; when b=2, T_(b) is alkylene of 2to 12 carbon atoms, cycloalkylene of 6 to 10 carbon atoms, arylene of 6to 10 carbon atoms or alkylenearylenealkylene of 8 to 10 carbon atoms orT_(a) and T_(b) together with the two nitrogens can form a 5-7 membersaturated heterocyclic ring; when b=3, T_(b) is alkanetriyl of 3 to 6carbon atoms or T_(a) and T_(b) together with the three nitrogens canform a 5-6 member saturated heterocyclic ring; and when b=4, T_(b) isalkanetetriyl of 4 to 6 carbon atoms; e) amine oxide stabilizers offormula (VII) wherein G₁ and G₂ are independently alkyl groups of 8 to26 carbon atoms and G₃ is methyl; f) benzofuranone stabilizers selectedfrom the group consisting of3-(4-(2-acetoxyethoxy)phenyl)-5,7-di-tert-butyl-benzofuran-2-one,5,7-di-tert-butyl-3-(4-(2-stearoyloxyethoxy)phenyl)benzofuran-2-one,3,3′-bis(5,7-di-tert-butyl-3-(4-(2-hydroxyethoxy)phenyl)benzofuran-2-one),5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one,3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one,3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-tert-butyl-benzofuran-2-one,3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one and3-(2,3-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one; g) phosphitesand phosphonites selected from the group consisting of triphenylphosphite, tris(nonylphenyl) phosphite, trilauryl phosphite,trioctadecyl phosphite, distearyl pentaerythritol diphosphite,tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritoldiphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite,bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite,bisisodecyloxypentaerythritol diphosphite,bis(2,4-di-tert-butyl-6-methylphenyl) pentaerythritol diphosphite,bis(2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tristearylsorbitol triphosphite, tetrakis (2,4-di-tert-butylphenyl)4,4′-biphenylene-diphosphonite,6-isooctyloxy-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin,6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyldibenzo[d,g][1,3,2]dioxaphosphocin,bis(2,4-di-tert-butyl-6-methylphenyl) methyl phosphite,bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite and2,2′,2″-nitrilo[triethyltris(3,3′5,′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite],

h) quinone methide stabilizers selected from the group consisting of(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetonitrile,(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetic acid,(3,5-di-tert-amyl-4-oxocyclohexa-2,5-dienylidene)acetic acid, methyl(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetate, ethyl(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetate, n-butyl(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetate,2,6-di-tert-butyl-4-(2-oxopropylidene)-cyclohexa-2,5-dienone, diethyl(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methanephosphonate,(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methyl acetate,(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methyl pivalate,(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methyl benzoate, andN,N-diethyl-2-(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetamide,2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone,2,6-di-tert-butyl-4-(4-nitrobenzylidene)-cyclohexa-2,5-dienone,2,6-di-tert-butyl-4-(3-nitrobenzylidene)-cyclohexa-2,5-dienone,2,6-di-tert-butyl-4-(4-cyanobenzylidene)-cyclohexa-2,5-dienone,2,6-di-tert-butyl-4-(4-dimethylaminobenzylidene)-cyclohexa-2,5-dienone,2,6-di-tert-amyl-4-benzylidene-cyclohexa-2,5-dienone,2,6-di-tert-butyl-4-(4-methoxybenzylidene)-cyclohexa-2,5-dienone, and2,6-di-tert-butyl-4-(3,5-di-tert-butyl-4-hydroxybenzylidene)-cyclohexa-2,5-dienone; j) monoacrylate estersselected from the group consisting of2,2′-methylenebis(6-tert-butyl-4-methylphenol),2,2′-methylenebis(6-tert-butyl-4-ethylphenol),2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol]2,2′-methylenebis(4-methyl-6-cyclohexylphenol),2,2′-methylenebis(6-nonyl-4-methylphenol),2,2′-methylenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol),2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],2,2′-methylenebis[6-(α,α-dimethylbenzyl)4-nonylphenol],2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol and1,1-bis-(3,5-dimethyl-2-hydroxypheny)butane.
 4. A composition accordingto claim 3 wherein component (i.) of the synergistic mixture (B) isselected from a) nitroxyl stabilizers; b)N,N-dihydrocarbylhydroxylamines selected from the group consisting ofN,N-dibenzylhydroxylamine, N,N-diethylhydroxylamine,N,N-dioctylhydroxylamine, N,N-dilaurylhydroxylamine,N,N-didodecylhydroxylamine, N,N-ditetradecylhydroxylamine,N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine,N-hexadecyl-N-tetradecylhydroxylamine,N-hexadecyl-N-heptadecylhydroxylamine,N-hexadecyl-N-octadecylhydroxylamine,N-heptadecyl-N-octadecylhydroxylamine, N-methyl-N-octadecylhydroxylamineand N,N-di(hydrogenated tallow)hydroxylamine; f) benzofuranonestabilizers selected from the group consisting of


5. A composition according to claim 1 in which component (ii.) of thesynergistic mixture (B) is at least one compound selected from the groupconsisting of tetraphenyl resorcinol diphosphite, chloroalkyl phosphateesters, polybrominated diphenyl oxide, decabromodiphenyl oxide, antimonytrioxide, antimony pentoxide, tris[3-bromo-2,2-bis(bromomethyl)propyl]phosphate, triphenyl phosphate, bis(2,3-dibromopropyl ether) ofbisphenol A, ammonium polyphosphate, resorcinol diphosphate oligomer,brominated epoxy resin, ethylene-bis(tetrabromophthalimide),bis(hexachlorocyclopentadieno)cyclooctane, calcium sulfate, chlorinatedparaffins, magnesium carbonate, melamine phosphates, melaminepyrophosphates, molybdenum trioxide, zinc oxide,1,2-bis(tribromophenoxy)ethane, tetrabromo-bisphenol A, magnesiumhydroxide, alumina trihydrate, zinc borate, ethylenediamine diphosphate,silica, silicones, calcium silicate, magnesium silicate and ethylenebis-(dibromo-norbornanedicarboximide).
 6. A composition according toclaim 1 in which component (i.) of the synergistic mixture (B) is atleast one compound selected from the group consisting of (a)bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate,4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine, (b) anN,N-di(alkyl)hydroxylamine produced by the direct oxidation ofN,N-di(hydrogenated tallow)amine, (c) N-octadecyl-α-heptadecylnitrone,(d) O-n-propyl-N,N-dioctadecylhydroxylamine, (e) di(C₁₆-C₁₈)alkyl methylamine oxide, (f)3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one, (g)tris(2,4-di-tert-butylphenyl) phosphite, (h)2,6-di-tert-butyl-4-benzylidene-cyclohexa-2,5-dienone and (j)monoacrylate ester of 2,2′-methylenebis(6-tert-butyl-4-methylphenol) andcomponent (ii.) of the synergistic mixture (B) is at least one compoundselected from the group consisting of polybrominated diphenyl oxide,decabromodiphenyl oxide, bis(2,3-dibromopropyl ether) of bisphenol A,ammonium polyphosphate, resorcinol diphosphate oligomer, brominatedepoxy resin, ethylene-bis(tetrabromophthalimide),1,2-bis(tribromophenoxy)ethane and tetrabromo-bisphenol A.
 7. Acomposition according to claim 1 or 6 in which component (ii.) of thesynergistic mixture (B) is the flame retardant ammonium polyphosphate ordecabromodiphenyl oxide.
 8. A composition according to claim 1 whereinof the synergistic mixture (B), component (i.) is present from 0.25 to10% by weight, based on component (A); and component (ii.) is presentfrom 0.25 to 60% by weight, based on component (A).
 9. A compositionaccording to claim 1 further comprising a UV absorber.
 10. A compositionaccording to claim 9 comprising a UV absorber selected from the groupconsisting of 2-(2-hydroxy-3,5-di-α-cumylphenyl)-2H-benzotriazole,2-(2-hydroxy-5methylphenyl)-2H-benzotriazole,5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole,triazole, 2-(2-hydroxy-3,5-di-tert-amylphenyl)-2H-benzotriazole,2-(2-hydroxy-3-α-cumyl-5tert-octylphenyl)2H-benzotriazole,2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate,2-hydroxy-4-n-octyloxybenzophenone and2,4-bis(2,4-dimethyphenyl)-6-(2hydroxy-4-octyloxyphenyl)-s-triazine. 11.A composition according to claim 1 wherein the polymer substrate (A) isselected from the group of resins consisting of the polyolefins, thethermoplastic olefins, styrenic polymers and copolymers.
 12. Acomposition according to claim 11 wherein the polymer substrate (A) isselected from the group consisting of polypropylene, polyethylene,thermoplastic olefin, acrylnitrile/butadiene/styrene copolymer and highimpact polystyrene.
 13. A composition according to claim 1 whereincomponent (i.) of the synergistic mixture (B) is present in an amountfrom 5.1 to 10% by weight based on the polymer substrate (A).